On the Multi-Instanton Measure for Super Yang--Mills Theories

In this paper we revisit the arguments that have led to the proposal of a multi-instanton measure for supersymmetric Yang-Mills theories. We then recall how the moduli space of gauge connections on $\real^4$ can be built from a hyperk\"ahler quotient construction which we generalize to supermanifolds. The measure we are looking for is given by the supermetric of the supermoduli space thus introduced. To elucidate the construction we carry out explicit computations in the case of N=2 supersymmetric Yang-Mills theories.Comment: 28 pages, latex fil

Instanton Calculus, Topological Field Theories and N=2 Super Yang-Mills Theories

The results obtained by Seiberg and Witten for the low-energy Wilsonian effective actions of N=2 supersymmetric theories with gauge group SU(2) are in agreement with instanton computations carried out for winding numbers one and two. This suggests that the instanton saddle point saturates the non-perturbative contribution to the functional integral. A natural framework in which corrections to this approximation are absent is given by the topological field theory built out of the N=2 Super Yang-Mills theory. After extending the standard construction of the Topological Yang-Mills theory to encompass the case of a non-vanishing vacuum expectation value for the scalar field, a BRST transformation is defined (as a supersymmetry plus a gauge variation), which on the instanton moduli space is the exterior derivative. The topological field theory approach makes the so-called "constrained instanton" configurations and the instanton measure arise in a natural way. As a consequence, instanton-dominated Green's functions in N=2 Super Yang-Mills can be equivalently computed either using the constrained instanton method or making reference to the topological twisted version of the theory. We explicitly compute the instanton measure and the contribution to u=<\Tr \phi^2> for winding numbers one and two. We then show that each non-perturbative contribution to the N=2 low-energy effective action can be written as the integral of a total derivative of a function of the instanton moduli. Only instanton configurations of zero conformal size contribute to this result. Finally, the 8k-dimensional instanton moduli space is built using the hyperkahler quotient procedure, which clarifies the geometrical meaning of our approach.Comment: latex, 66 page

Novel homozygous GBA2 mutation in a patient with complicated spastic paraplegia

Hereditary spastic paraplegias (HSPs) are a heterogeneous group of neurological disorders characterized primarily by a pyramidal syndrome with lower limb spasticity, which can manifest as pure HSP or associated with a number of neurological or non-neurological signs (i.e., complicated HSPs). The clinical variability of HSPs is associated with a wide genetic heterogeneity, with more than eighty causative genes known. Recently, next generation sequencing (NGS) has allowed increasing genetic definition in such a heterogeneous group of disorders. We report on a 56- year-old man affected by sporadic complicated HSP consisting of a pyramidal syndrome, cerebellar ataxia, congenital cataract, pes cavus, axonal sensory-motor peripheral neuropathy and cognitive decline. Brain MRI showed cerebellar atrophy and thin corpus callosum. By NGS we found a novel homozygous biallelic c.452-1G > C mutation in the b-glucosidase 2 gene (GBA2), known to be causative for autosomal recessive hereditary spastic paraplegia type 46 (SPG46). The rarity of this inherited form besides reporting on a novel mutation, expands the genetic and clinical spectrum of SPG46 related HSP

Relationship between tree-related microhabitats and the captures obtained using different trap methods for large threatened saproxylic beetles

Osmoderma eremita and Cerambyx cerdo are saproxylic beetle species, included in the IUCN Red List and in the EU/92 Habitats Directive. Their occurrence has been recorded, through appropriate traps, in several localities in Italy, including urban and peri-urban parks, mostly associated with veteran trees. In this study, traps were tested over 17 veteran oak trees in the Castelporziano Presidential Estate (Latium, Rome province, central Italy) and the abundance of sampled saproxylic beetles was related to the growing stock volume (GSV) and the abundance of microhabitats. Moreover, we compared three different trapping methods: a trap designed to monitor C. cerdo (CC), and two traps designed for monitoring O. eremita, i.e., the Black Cross Window Trap (BCWT) and the Black Bottle Traps (BBT). We found that larger trees hosted a great variety of microhabitats, in particular cavities, which abundance was correlated with the number of specimens sampled, especially O. eremita species. Both classic traps (i.e., CC traps and BCWT) and the herein-introduced BBT variants were effective for capturing large saproxylic beetles. In this work, we underline the importance of the preservation of veteran trees to the occurrence of threatened saproxylic beetles, and we contributed to (i) extending general knowledge of the habitat preferences of saproxylic beetles and (ii) improving new cost-effective trapping system variants

Stand structure attributes in potential Old-Growth Forests in the Apennines, Italy

The aim of this paper is to provide early feedback on stand structure attributes in Italian Apennines forests that could be considered Old Growth Forests in the Mediterranean Eco-Region. Few data are nowadays available relating to this Region. 10 forest reserves across the Apennines were selected and a census of trees and structural parameters was conducted in permanent plots (0.16-1.0 ha), one plot for each selected forest stand. Dimensional and structural characters indicate a large variability among the investigated forest stands. The considered parameters are compared with those reported for other European countries. Old growth features and characteristics of each indicator should be revised and referred to the particular climatic and biogeographic context. The chosen forest study sites are to be considered old if related to common Apennine stands but, in some cases, their development stage is not so close to “truly” Old Growth Forest. Permanent plots allow future investigations on dynamic processes leading to real Old Growth Mediterranean Forests in Italian Apennines

Adoption of new silvicultural methods in Mediterranean forests: the influence of educational background and sociodemographic factors on marker decisions

Producción Científica- Key message The adoption of new silvicultural methods and approaches requires an understanding of the differences between those and “old” or “conventional” approaches, along with extensive training to break previous knowledge bias. - Context Forestry is in transition towards ecosystem-based management, and new silvicultural approaches are appearing worldwide. However, the adoption of an alternative silvicultural approach is difficult in practice. - Aims We analyzed the effect of forestry background and demographic variables (gender and age) of 24 raters on the application of the systemic approach (SA) and the conventional approach (CA) in the Northern Apennines (Italy) and compared this with tree marking performed by experts. - Methods Data were analyzed as raters’ departures from experts’ selections at the stand and the individual tree level. The probability of tree selection was also calculated. - Results At the stand level, raters with forestry background performed the SA as if they were marking for crown thinning, whereas the CA was less intense than experts’ crown thinning. Non-foresters differentiated poorly between the SA and the CA. At the individual tree level, background and gender affected tree selection. - Conclusion The adoption of the SA as a silvicultural system may be conditioned by previous knowledge. The difference between SA and CA remains unclear when it comes to non-foresters. Gender was a more important variable than age in selecting which trees would be harvested

Instanton Calculus and Nonperturbative Relations in N=2 Supersymmetric Gauge Theories

Using instanton calculus we check, in the weak coupling region, the nonperturbative relation =i\pi\left(\cf-{a\over 2} {\partial\cf\over\partial a}\right) obtained for a N=2 globally supersymmetric gauge theory. Our computations are performed for instantons of winding number k, up to k=2 and turn out to agree with previous nonperturbative results.Comment: 18 pages, latex file, no figure

Bleeding risk evaluation in cerebral cavernous malformation, the role of medications, and hemorrhagic factors: a case-control study

Objective: Cerebral cavernous malformations (CCMs) are vascular lesions with an overall risk of rupture from 2% to 6% per year, which is associated with significant morbidity and mortality. The diagnostic incidence is increasing, so it is of paramount importance to stratify patients based on their risk of rupture. Data in the literature seem to suggest that specific medications, particularly antithrombotic and cardiovascular agents, are associated with a reduced risk of bleeding. However, the effect of the patient coagulative status on the cumulative bleeding risk remains unclear. The aim of this study was to assess the impact of different radiological, clinical, and pharmacological factors on the bleeding risk of CCMs and to assess the predictive power of an already validated scale for general bleeding risk, the HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly). Method: This was a multicenter retrospective observational study. The authors collected imaging, clinical status, and therapy data on patients with bleeding and nonbleeding CCMs. Univariate analysis and subsequent multivariate logistic regression were performed between the considered variables and bleeding or nonbleeding status to identify potential independent predictors of bleeding. Results: The authors collected data on 257 patients (46.7% male, 25.3% with bleeding CCMs). Compared with patients with nonbleeding lesions, those with bleeding CCMs were younger, less frequently had hypertension, and less frequently required antiplatelet drugs and beta-blockers (all p &lt; 0.05). Bleeding lesions, however, had significantly higher median volumes (1050 mm3 vs 523 mm3 , p &lt; 0.001). On multivariate analyses, after adjusting for age, history of hypertension and diabetes, and use of antiplatelet drugs or beta-blockers, lesion volume ≥ 300 mm3 was the only significant predictor of bleeding (adjusted OR 3.11, 95% CI 1.09-8.86). When the diagnostic accuracy of different volume thresholds was explored, volume ≥ 300 mm3 showed a limited sensitivity (36.7%, 95% CI 24.6%-50.0%), but a high specificity 78.2% (95% CI 71.3%-84.2%), with an area under the curve of 0.57 (95% CI 0.51-0.64). Conclusions: This study supports previous findings that the CCM volume is the only factor influencing the bleeding risk. Antithrombotic agents and propranolol seem to have a protective role against the bleeding events. A high HAS-BLED score was not associated with an increased bleeding risk. Further studies are needed to confirm these results

Real-life effectiveness of tildrakizumab in chronic plaque psoriasis: A 52-week multicentre retrospective study—IL PSO (Italian landscape psoriasis)

Background: Tildrakizumab is a humanized monoclonal antibody that binds selectively the p19 subunit of interleukin-23. It is approved for treatment of moderate– severe chronic plaque psoriasis. Objectives: We conducted a 52-week retrospective study to assess the effectiveness and safety of tildrakizumab in a real-life setting. Methods: Our retrospective study included 237 consecutive adults with moderateto-severe plaque psoriasis, enrolled in 10 different Italian centres, treated with tildrakizumab up to Week 52. Patient characteristics, comorbidities, previous treatmentsand the PASI (Psoriasis Area and Severity Index) score at each visit (baseline, Week 16, Week 28 and Week 52) were retrieved from the electronic medical records. The percentages of patients achieving 75%, 90% and 100% (PASI 75, PASI 90 and PASI 100) improvement in PASI with respect to baseline PASI were registered. Results: At Week 52, 90.91%, 73.55% and 58.68% of patients achieved a PASI reduction ≥75% (PASI 75), PASI 90 and PASI 100, respectively. An absolute PASI≤2 was reached by 85.95% at Week 52. Compared with Phase 3 clinical trials, we observed similar rates of PASI 75/90 responses and higher percentages of patients achieving PASI 100. Patients who had not responded to previous biologic treatments and patients with cardio-metabolic comorbidities were significantly more likely to achieve PASI 100 at Week 28 and PASI 90 at Week 52. The higher body mass index did not interfere with the odds of reaching PASI 75/90/100 at each time point. No significant safety findings were recorded throughout the study, and none of the patients had to interrupt the treatment because of adverse events. Conclusion: Our data suggest that the efficacy of tildrakizumab for plaque psoriasis in ‘real-life’ clinical practice is comparable with Phase 3 clinical trials with higher percentages of patients achieving complete skin clearance (PASI 100) at Weeks 16, 28 and 52

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009.

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached